Free converter
XLSXLSXXLS to XLSX Converter
The old .xls format caps out at 65,536 rows and is blocked by a growing number of mail and security policies. Converting to XLSX lifts the limit and makes the file ordinary again — locally, in batches, for free.
Drop in your files — An .xlsx per workbook, in the folder you choose.
Why convert
Why convert XLS to XLSX?
XLS is the pre-2007 Excel format: a hard 65,536-row ceiling, larger files, and a macro container that many organisations now block. XLSX removes all three problems and is what every current spreadsheet application expects.
- An old workbook has hit the 65,536-row limit.
- Email or security policy is rejecting legacy Office attachments.
- You are modernising an archive of old spreadsheets in one pass.
- A tool downstream requires XLSX specifically.
How it works
Convert XLS to XLSX in a few clicks
- 1
Open Office Converter
Choose it from the tray — no download needed for tabular conversions.
- 2
Add the XLS files
One workbook or a whole archive folder.
- 3
Select XLSX
Pick it as the target format.
- 4
Convert
Set the output folder and run.
The details
XLS to XLSX, at a glance
- Input
- XLS (Excel 97–2003)
- Output
- XLSX, with a row ceiling of 1,048,576 instead of 65,536
- Multiple sheets
- Every sheet is carried across
- Macros
- Not carried into the output
- Engine download
- None — tabular paths do not need it
- Limits
- No file-size cap, no watermark
Questions
XLS to XLSX Converter, answered
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Convert XLS to XLSX — free
It's one tool inside BizTray, alongside the PDF Organizer, PDF Tools, and Fill & Sign. One small download, no account.
Local, private, no watermark.